The workshop “Torsors: theory and applications” took place at the International Centre for Mathematical Sciences in Edinburgh from 10 – 14 January 2011. It was organised by Victor Batyrev and myself, and was funded by EPSRC and LMS. The aim was to bring together mathematicians who work with torsors from different perspectives such as geometric invariant theory, algebraic geometry, representation theory, non-abelian cohomology, and those who apply torsors in arithmetic geometry.

This collection contains the lecture notes of two mini-courses presented at the workshop by Jürgen Hausen and Vera Serganova, as well as the papers contributed by participants. It also contains lecture notes of a mini-course on étale homotopy by Tomer Schlank from the study group organised in Imperial College in the Autumn of 2010 (edited by Tomer Schlank and myself).